Yeah they look cool. But from the tests, I get the feeling that on lower RPM of the fan they give just a little worse results versus the ones with no nickel/other plating on. With the higher RPM it's the same basically.

Love the look of Asrocks boards, I have a Z68 Extreme7 that should be here Friday

Painting the bridge shouldnt be an issue, although since it flexes it may eventually crack (guess you can just be careful). When I ran a Xfire setup I was tempted to use that imitation carbon fiber wrap that they sell in automotive stores to cover the bridge with. I don't think its too expensive.